1 files changed, 372 insertions, 0 deletions

diff --git a/arch/xtensa/platforms/iss/simdisk.c b/arch/xtensa/platforms/iss/simdisk.c
new file mode 100644
index 000000000..026211e7a
--- /dev/null
+++ b/arch/xtensa/platforms/iss/simdisk.c
@@ -0,0 +1,372 @@
+/*
+ * arch/xtensa/platforms/iss/simdisk.c
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2001-2013 Tensilica Inc.
+ *   Authors	Victor Prupis
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/string.h>
+#include <linux/blkdev.h>
+#include <linux/bio.h>
+#include <linux/proc_fs.h>
+#include <linux/uaccess.h>
+#include <platform/simcall.h>
+
+#define SIMDISK_MAJOR 240
+#define SIMDISK_MINORS 1
+#define MAX_SIMDISK_COUNT 10
+
+struct simdisk {
+	const char *filename;
+	spinlock_t lock;
+	struct request_queue *queue;
+	struct gendisk *gd;
+	struct proc_dir_entry *procfile;
+	int users;
+	unsigned long size;
+	int fd;
+};
+
+
+static int simdisk_count = CONFIG_BLK_DEV_SIMDISK_COUNT;
+module_param(simdisk_count, int, S_IRUGO);
+MODULE_PARM_DESC(simdisk_count, "Number of simdisk units.");
+
+static int n_files;
+static const char *filename[MAX_SIMDISK_COUNT] = {
+#ifdef CONFIG_SIMDISK0_FILENAME
+	CONFIG_SIMDISK0_FILENAME,
+#ifdef CONFIG_SIMDISK1_FILENAME
+	CONFIG_SIMDISK1_FILENAME,
+#endif
+#endif
+};
+
+static int simdisk_param_set_filename(const char *val,
+		const struct kernel_param *kp)
+{
+	if (n_files < ARRAY_SIZE(filename))
+		filename[n_files++] = val;
+	else
+		return -EINVAL;
+	return 0;
+}
+
+static const struct kernel_param_ops simdisk_param_ops_filename = {
+	.set = simdisk_param_set_filename,
+};
+module_param_cb(filename, &simdisk_param_ops_filename, &n_files, 0);
+MODULE_PARM_DESC(filename, "Backing storage filename.");
+
+static int simdisk_major = SIMDISK_MAJOR;
+
+static void simdisk_transfer(struct simdisk *dev, unsigned long sector,
+		unsigned long nsect, char *buffer, int write)
+{
+	unsigned long offset = sector << SECTOR_SHIFT;
+	unsigned long nbytes = nsect << SECTOR_SHIFT;
+
+	if (offset > dev->size || dev->size - offset < nbytes) {
+		pr_notice("Beyond-end %s (%ld %ld)\n",
+				write ? "write" : "read", offset, nbytes);
+		return;
+	}
+
+	spin_lock(&dev->lock);
+	while (nbytes > 0) {
+		unsigned long io;
+
+		simc_lseek(dev->fd, offset, SEEK_SET);
+		READ_ONCE(*buffer);
+		if (write)
+			io = simc_write(dev->fd, buffer, nbytes);
+		else
+			io = simc_read(dev->fd, buffer, nbytes);
+		if (io == -1) {
+			pr_err("SIMDISK: IO error %d\n", errno);
+			break;
+		}
+		buffer += io;
+		offset += io;
+		nbytes -= io;
+	}
+	spin_unlock(&dev->lock);
+}
+
+static blk_qc_t simdisk_make_request(struct request_queue *q, struct bio *bio)
+{
+	struct simdisk *dev = q->queuedata;
+	struct bio_vec bvec;
+	struct bvec_iter iter;
+	sector_t sector = bio->bi_iter.bi_sector;
+
+	bio_for_each_segment(bvec, bio, iter) {
+		char *buffer = kmap_atomic(bvec.bv_page) + bvec.bv_offset;
+		unsigned len = bvec.bv_len >> SECTOR_SHIFT;
+
+		simdisk_transfer(dev, sector, len, buffer,
+				bio_data_dir(bio) == WRITE);
+		sector += len;
+		kunmap_atomic(buffer);
+	}
+
+	bio_endio(bio);
+	return BLK_QC_T_NONE;
+}
+
+static int simdisk_open(struct block_device *bdev, fmode_t mode)
+{
+	struct simdisk *dev = bdev->bd_disk->private_data;
+
+	spin_lock(&dev->lock);
+	if (!dev->users)
+		check_disk_change(bdev);
+	++dev->users;
+	spin_unlock(&dev->lock);
+	return 0;
+}
+
+static void simdisk_release(struct gendisk *disk, fmode_t mode)
+{
+	struct simdisk *dev = disk->private_data;
+	spin_lock(&dev->lock);
+	--dev->users;
+	spin_unlock(&dev->lock);
+}
+
+static const struct block_device_operations simdisk_ops = {
+	.owner		= THIS_MODULE,
+	.open		= simdisk_open,
+	.release	= simdisk_release,
+};
+
+static struct simdisk *sddev;
+static struct proc_dir_entry *simdisk_procdir;
+
+static int simdisk_attach(struct simdisk *dev, const char *filename)
+{
+	int err = 0;
+
+	filename = kstrdup(filename, GFP_KERNEL);
+	if (filename == NULL)
+		return -ENOMEM;
+
+	spin_lock(&dev->lock);
+
+	if (dev->fd != -1) {
+		err = -EBUSY;
+		goto out;
+	}
+	dev->fd = simc_open(filename, O_RDWR, 0);
+	if (dev->fd == -1) {
+		pr_err("SIMDISK: Can't open %s: %d\n", filename, errno);
+		err = -ENODEV;
+		goto out;
+	}
+	dev->size = simc_lseek(dev->fd, 0, SEEK_END);
+	set_capacity(dev->gd, dev->size >> SECTOR_SHIFT);
+	dev->filename = filename;
+	pr_info("SIMDISK: %s=%s\n", dev->gd->disk_name, dev->filename);
+out:
+	if (err)
+		kfree(filename);
+	spin_unlock(&dev->lock);
+
+	return err;
+}
+
+static int simdisk_detach(struct simdisk *dev)
+{
+	int err = 0;
+
+	spin_lock(&dev->lock);
+
+	if (dev->users != 0) {
+		err = -EBUSY;
+	} else if (dev->fd != -1) {
+		if (simc_close(dev->fd)) {
+			pr_err("SIMDISK: error closing %s: %d\n",
+					dev->filename, errno);
+			err = -EIO;
+		} else {
+			pr_info("SIMDISK: %s detached from %s\n",
+					dev->gd->disk_name, dev->filename);
+			dev->fd = -1;
+			kfree(dev->filename);
+			dev->filename = NULL;
+		}
+	}
+	spin_unlock(&dev->lock);
+	return err;
+}
+
+static ssize_t proc_read_simdisk(struct file *file, char __user *buf,
+			size_t size, loff_t *ppos)
+{
+	struct simdisk *dev = PDE_DATA(file_inode(file));
+	const char *s = dev->filename;
+	if (s) {
+		ssize_t n = simple_read_from_buffer(buf, size, ppos,
+							s, strlen(s));
+		if (n < 0)
+			return n;
+		buf += n;
+		size -= n;
+	}
+	return simple_read_from_buffer(buf, size, ppos, "\n", 1);
+}
+
+static ssize_t proc_write_simdisk(struct file *file, const char __user *buf,
+			size_t count, loff_t *ppos)
+{
+	char *tmp = memdup_user_nul(buf, count);
+	struct simdisk *dev = PDE_DATA(file_inode(file));
+	int err;
+
+	if (IS_ERR(tmp))
+		return PTR_ERR(tmp);
+
+	err = simdisk_detach(dev);
+	if (err != 0)
+		goto out_free;
+
+	if (count > 0 && tmp[count - 1] == '\n')
+		tmp[count - 1] = 0;
+
+	if (tmp[0])
+		err = simdisk_attach(dev, tmp);
+
+	if (err == 0)
+		err = count;
+out_free:
+	kfree(tmp);
+	return err;
+}
+
+static const struct file_operations fops = {
+	.read = proc_read_simdisk,
+	.write = proc_write_simdisk,
+	.llseek = default_llseek,
+};
+
+static int __init simdisk_setup(struct simdisk *dev, int which,
+		struct proc_dir_entry *procdir)
+{
+	char tmp[2] = { '0' + which, 0 };
+
+	dev->fd = -1;
+	dev->filename = NULL;
+	spin_lock_init(&dev->lock);
+	dev->users = 0;
+
+	dev->queue = blk_alloc_queue(GFP_KERNEL);
+	if (dev->queue == NULL) {
+		pr_err("blk_alloc_queue failed\n");
+		goto out_alloc_queue;
+	}
+
+	blk_queue_make_request(dev->queue, simdisk_make_request);
+	dev->queue->queuedata = dev;
+
+	dev->gd = alloc_disk(SIMDISK_MINORS);
+	if (dev->gd == NULL) {
+		pr_err("alloc_disk failed\n");
+		goto out_alloc_disk;
+	}
+	dev->gd->major = simdisk_major;
+	dev->gd->first_minor = which;
+	dev->gd->fops = &simdisk_ops;
+	dev->gd->queue = dev->queue;
+	dev->gd->private_data = dev;
+	snprintf(dev->gd->disk_name, 32, "simdisk%d", which);
+	set_capacity(dev->gd, 0);
+	add_disk(dev->gd);
+
+	dev->procfile = proc_create_data(tmp, 0644, procdir, &fops, dev);
+	return 0;
+
+out_alloc_disk:
+	blk_cleanup_queue(dev->queue);
+	dev->queue = NULL;
+out_alloc_queue:
+	simc_close(dev->fd);
+	return -EIO;
+}
+
+static int __init simdisk_init(void)
+{
+	int i;
+
+	if (register_blkdev(simdisk_major, "simdisk") < 0) {
+		pr_err("SIMDISK: register_blkdev: %d\n", simdisk_major);
+		return -EIO;
+	}
+	pr_info("SIMDISK: major: %d\n", simdisk_major);
+
+	if (n_files > simdisk_count)
+		simdisk_count = n_files;
+	if (simdisk_count > MAX_SIMDISK_COUNT)
+		simdisk_count = MAX_SIMDISK_COUNT;
+
+	sddev = kmalloc_array(simdisk_count, sizeof(*sddev), GFP_KERNEL);
+	if (sddev == NULL)
+		goto out_unregister;
+
+	simdisk_procdir = proc_mkdir("simdisk", 0);
+	if (simdisk_procdir == NULL)
+		goto out_free_unregister;
+
+	for (i = 0; i < simdisk_count; ++i) {
+		if (simdisk_setup(sddev + i, i, simdisk_procdir) == 0) {
+			if (filename[i] != NULL && filename[i][0] != 0 &&
+					(n_files == 0 || i < n_files))
+				simdisk_attach(sddev + i, filename[i]);
+		}
+	}
+
+	return 0;
+
+out_free_unregister:
+	kfree(sddev);
+out_unregister:
+	unregister_blkdev(simdisk_major, "simdisk");
+	return -ENOMEM;
+}
+module_init(simdisk_init);
+
+static void simdisk_teardown(struct simdisk *dev, int which,
+		struct proc_dir_entry *procdir)
+{
+	char tmp[2] = { '0' + which, 0 };
+
+	simdisk_detach(dev);
+	if (dev->gd)
+		del_gendisk(dev->gd);
+	if (dev->queue)
+		blk_cleanup_queue(dev->queue);
+	remove_proc_entry(tmp, procdir);
+}
+
+static void __exit simdisk_exit(void)
+{
+	int i;
+
+	for (i = 0; i < simdisk_count; ++i)
+		simdisk_teardown(sddev + i, i, simdisk_procdir);
+	remove_proc_entry("simdisk", 0);
+	kfree(sddev);
+	unregister_blkdev(simdisk_major, "simdisk");
+}
+module_exit(simdisk_exit);
+
+MODULE_ALIAS_BLOCKDEV_MAJOR(SIMDISK_MAJOR);
+
+MODULE_LICENSE("GPL");